1. Field
One or more embodiments relate to a robot cleaner for creating a pattern capable of enhancing the efficiency of cleaning, and a control method thereof.
2. Description of the Related Art
In general, a robot cleaner automatically cleans an area to be cleaned by sucking up foreign substances such as dust from a floor while autonomously traveling about the cleaning area without user manipulation.
During cleaning, the robot cleaner determines a distance to an obstacle, e.g., furniture, office appliances, walls, etc., present in the cleaning area using a sensor, and travels about the cleaning area without collision with the obstacle based on the determined distance.
Cleaning a given cleaning area using the robot cleaner means an operation in which the robot cleaner repeatedly travels about the cleaning area along a pre-set traveling pattern to clean the cleaning area, wherein the pre-set traveling pattern is, for example, a zig-zag pattern, a spiral pattern, a random pattern, etc.
The zig-zag pattern has been designed to repeatedly perform, in a predetermined area, operation of moving along a straight line, stopping at a direction-change point to rotate by 90° with respect to the moving direction, then moving along a straight line by a predetermined distance, again stopping to rotate by 90° in the opposite direction of the moving direction, and then moving along a straight line. After the robot cleaner travels all over the predetermined region in the zig-zag pattern, the robot cleaner repeatedly travels the same region to improve coverage.
The zig-zag pattern shows uniform cleaning coverage until cleaning is completed, but has lower coverage than the random pattern if there is no repeated traveling.
Also, the zig-zag pattern requires two stops and two rotations to change the travel direction, and needs a long time for direction change since an acceleration/deceleration velocity profile is applied for stops and rotations.
Furthermore, upon stops and rotations for direction change during cleaning based on the zig-zag pattern, the robot cleaner tends to spill collected dust. Particularly, in the case of wet cleaning, the robot cleaner may spill a large quantity of dust at direction-change points since it wipes off dust with a rag instead of sucking dust up.
In addition, the robot cleaner has a problem that dust is gathered between a main brush and a blade made of a soft material, the blade installed in a reverse-inclined direction in the back of the brush. Particularly, a blade made with the soft material often tilts back when the robot cleaner moves, which widens the distance from the main brush.